Building / Populating a Drop Down Menu on Web Page from Google Spreadsheet Data

I'm using a Google visualization query to pull column headings from this spreadsheet. Currently I must include the row and column indexes for each cell I want in the menu. What I'd like is a script that'll populate this menu dynamically with data from the cells in row 1 of the spreadsheet. In other words, make the menu as big or as small as what exists on the spreadsheet.

I believe I need something like the following, but I'm unsure how to implement it. Perhaps I need server side script (GAS) to accomplish this??